The present invention relates to a lavatory for connection to a composting container or a sewage pipe forming part of a sewage system, comprising a seat part, a lid adapted to the seat part, and a hollow support body supporting the seat part. The lavatory is particularly suitable for use in a composting toilet of the type comprising a composting container, a lavatory connected to the container and a ventilation duct with a fan leading off from the container.
Composting toilets of the type indicated above have been well-known for a long time and, from the environmental point of view, represent a considerably better alternative for handling biodegradable material than the water-flushing systems frequently used today, which are leading to serious and increasing environmental destruction. A more detailed description of the degradation process used is not included here as it is well-documented in patent literature.
In addition to permitting effective biodegradation of waste, a composting toilet must be hygienic and constructed in such a manner that no unpleasant odours arise in the toilet space. It must also be simple and inexpensive to produce and install and require as few components as possible.
A main object of the present invention is to produce a hygienic and practical lavatory which is suitable for use in dry toilets of the composting type. The invention aims in particular to solve the problem of faecal matter coming into contact with and adhering to the inner surface of the lavatory.
Another object is to produce such a lavatory which, when used in a composting toilet, contributes to effective ventilation of both the toilet space and the composting container.
According to the invention, the first object is achieved by means of a lavatory of the type indicated in the first paragraph, in which the support body surrounds or forms an inner duct through which faecal matter passes to the container or the sewage pipe, the rear wall of the duct sloping backwards from the seat part in the downward direction so that it forms an angle with the vertical.
The result of this sloping of the inner duct of the lavatory is that faecal matter will not, as is the case in previously known lavatories, come into contact with in particular the rear surface of the interior of the lavatory. Without water-flushing, this faecal matter dries and sticks to the inner surface, which is a problem for reasons of both hygiene and appearance.
The inner duct of the lavatory is suitably formed by a tubular drum, the drum sloping backwards from the seat part in the downward direction so that a longitudinal axis of the drum forms an angle with the vertical.
In a preferred embodiment, the slope of the drum is such that a point at the very rear on the delimiting edge of the upper opening of the drum is located essentially directly above the centre of the lower opening of the drum.
The second of the objects of the invention mentioned above is achieved by means of a lavatory according to the above, in which the drum is arranged in a surrounding support body so that a space is formed between the drum and the support body, which space or ducts arranged therein is or are connected to the space in the composting container, ventilation openings being arranged in the outer wall of the support body and/or the lid of the lavatory so that the toilet room is ventilated simultaneously with the composting container via said ventilation openings, said space and/or drum, the composting container and the ventilation duct.
The lavatory will thus constitute an active and essential part of the ventilation of the toilet room and the composting container. In this way, effective and cost-saving ventilation of both the toilet space and the composting container is achieved, with the use of only one ventilation duct with a fan.
The lavatory can also be made in the form of an economy-flush water toilet with an openable valve arrangement or a water trap in the drum, the upper part of the drum being made with ventilation openings so as also to allow ventilation of the space formed in the drum above the valve arrangement or the water trap via the space lying outside simultaneously with the ventilation of the toilet space.
It is preferred that the drum is arranged in a surrounding, essentially tubular support body. The slot-shaped space formed between the drum and the support body can be filled with an adhesive material which interconnects the drum and the support body to form what is known as a sandwich construction. For reasons of hygiene inter alia, at least the drum is made of stainless steel.
A composting toilet with a lavatory of this type is simple and inexpensive to produce, requires few components and brings about very effective ventilation of both the toilet space and the composting container. As the toilet space is ventilated via the lavatory and the composting container, the risk is eliminated of gases being drawn up though the lavatory to the toilet space as a consequence of extraction valves located therein.
Further features of the invention emerge from the patent claims below.